John Snow and Cholera

A British doctor, John Snow, played a major role in the discovery of the waterborne nature of cholera. During the second cholera pandemic in 1831, Snow was practicing in Soho, London. The river Thames, as Snow observed, was an open sewer. Its highly contaminated water was supplied as drinking water to the people of London and it had eventually killed many. In 1849, John Snow published the first account of his 'waterborne' theory.

In 1854, the first case of cholera death was reported in Soho, London. Within 10 days 500 local residents were dead. John Snow inspected the drinking habits of the victims of this outbreak. He found that people drew their drinking water from the Broad Street pump that was right outside. John Snow assumed that cholera might be caused by 'some as-yet-unidentified' infective particles in the sewage-contaminated water. John Snow also noticed that in the nearby workhouse an brewery, which had their own private water supplies, there were almost no casualties. Thus Snow showed that cholera was not directly transmitted through airborne particles, but by drinking contaminated water.

On September 1854, John Snow persuaded the authorities to remove the Broad Street pump's handle and the cases of cholera in that town were suddenly reduced dramatically.

Today, next to the site of the pump in Broad Street (now Broad Wick Street) in Soho, London is the John Snow Pub, which commemorates the significance of John Snow's discovery.